mitfan311

I own two 3.slows and ive pretty much memorized how to dissasemble and repair them. I once had a 98 but with 77k it never needed a thing. I have a co-worker with his well maintained 98 3.4 auto 2wd. over 220k. He has a new radiator so no strawbery milkshake. no engine codes but he says it runs weaker and mpgs are getting bad. I told him I would help him get it running right. I'm thinking, new air filter, new fuel filter, PCV, cap, rotor, wires maybe and new plugs. And 3 cans of seafoam over the course of the weekend. With no engine codes thats about all I can think of. Oh and then there is my crazy idea of running a half gallon of 60% seafoam and 40% gas at 43 psi (or whatever the OEM specs are) directly into the injectors at a bypass point after the fuel filter. I did it on my 3.0 and it worked well as long as someone stays on the gas. Made a big difference. But this isnt my truck so if I blow it up I have to buy it. I have the FSM. Any other thoughts?Wes

mitfan311

I need to make a list of the crazy but brilliant homemade/custom things ive done to repair or improve my 4runners and such.

KenC

Doesn't have cap and rotor,new fuel filter,new wires new plugs,new air filter and clean maf that's my recommendation

mitfan311

Yeah I just realized the cap and rotor part. 3 coils. I guess I will clean the MAF after reading posts on it. I just need to be careful. Im still going to run a half gallon of 60% seafoam & 40 % gas. When I remove the fuel filter I will use an adapter to run the mix into the line directly at about 40psi. Should make a big difference. Ive done it on my 95 and Ive done it with the injectors off the rail one at a time, you can see the murky crud as it sprays into a bowl.

KenC

Be careful with sea foam I've heard of a lot of problems caused by it especially on higher mile vehicles,personally I never used it and don't plan on it but good luck

Texas_Ace

Sounds like a good plan, particularly the MAF cleaning. Could also run a compression check while you are doing all of this to make sure everything is good internally.

I love seafoam, if you have a setup to inject it directly into the fuel line that is great. Run it for a little while like that and it will clean things out real good. Also send some though the intake and then shut it off to give it time to work.

I have a writeup on using seafoam around here someplace. I like to use some water first to soften everything up first. Marvel mystery oil also works good.

After all of that change the oil to clean out anything that got in it. See writeup for more info.

badattitude

I like to clean the throttle body real good too. Otherwise you have it covered. Be sure to ID the actual MAF wires and clean them. I cleaned the brown temp sendor the first time, before I realized the MAF wires are a little hidden. There are two MAF wires and they are silver.

I remove the MAF and Throttlebody for cleaning. It is a little bit of a pain to dis assemple that much but it really is better for cleaning.

mitfan311

Ok so I finished up on the tune up on this 1998 3.4 limited 2wd and I have pics and amazing video but dont know how to load them or share them on here so if anyone can help that would be awesome. This guy was the perfect candidate because of neglect and some other repair shops screw up. First thing was the air filter, beyond dirty. But what i saw behind it was a broken out hole big enough to suck in anything the size of a marble and maybe more. The hole was on the other side of the filter so naturally it was sucking in a great deal from there. My guess is that when they went to replace a coil a year ago they missed a bolt, got impatient and jerked the air box out leaving the hole. MAF cleaner was great CRC or something from Autozone. $8.00 I replaced all small vaccum lines and some larger ones. Others I pulled off and nipped the tip off for a new tighter grip. 223,000 miles. I ran several vac lines together using T adapters and seafoamed the hell out of it in 30 min intervals, half a can through the plenum evenly. Then used 1 & a half more bottles through PCV and other spots so there was no doubt it all got atomized and covered equally. It needed it. Fuel Filter ws straight forward but this is where I did the most insane thing. Disabled the fuel pump, took a cleaned out insecticide pump sprayer and pour a whole can of seafoam in it. Then added about a third of a seafoam bottle of regular gas. So I now have like a 70% seafoam 30% gas mix. I used about 2 feet of appropriate size fuel line, heavy duty bolt style hose clamps on the nozle and the other on the metal fuel line leading the the engine. I pumped the tank up to the max, taped the trigger handle down and started turning the engine over until it ran. It was chugging and struggling but it kept going back and forth between 500 and 1000RPMs. I couldnt give it gas because it would stall. So I sat the shop vac hose next to the tail pipe and let her run 70% seafoam for about 15 mins. Reassembled everything with a new fuel filter. cleared her out and went to change the plugs. The plugs were half NKG and the other 3 Denso. I understand thats how they come from the factory. I had no reason to believe they had ever been changed so I went with the NKG's you guys recommend. New PCV valve and an oil change. His back window didnt roll down. He said in 5 years he has had it it never did. So i took the paneling off and for whatever reason the motor was simply just unplugged. He was blown away at how much power he got back. He still cant believe how smooth and quick it is. he said he has had to get used to the new power. He's waiting on a trip to Nashville to see the MPG difference but he said he already knows its better. So I want to see about re-posting this with pics and video. I have them all on my laptop right off the sony cybershot I used. I will try to make a decent write up or something that can debunk some seafoam debates.

Texas_Ace

Sounds like a winner. If you are a shop you should consider getting a snap on motervac machine. It basically does what you were doing with the seafoam in the fuel line automatically. Great little system.

To share pictures or videos you need to upload them. I think this site supports attachments but better off with a place like photobucket.com

mitfan311

Well Im not a shop. I'm actually a surgical assistant. I spend most of my time repairing humans. It's funny, it doesnt matter if they are Japanese or American, they all have the same parts. And since I work in transplant surgery the organs are interchangeable. Lol. Actually they have to have matching blood types and certain tissue types but you get the idea. I have thought about purchasing a device like you're talking about. I should google it and get some info. The thing is, schrader valves. Ive seen them on the fuel injector lines to several newer GM and Chrysler vehicles. Is it the same Idea? Pull fuel pump fuse and use an air pump to canister with psi gauge style contraption? We cant do it on our 3.0's or 3.4's though (not under the hood with a schrader valve at least. I just like to have fun with 4Runners. Actually I will take apart anything to see how it works, even if it doesn't need fixing. Lol

mitfan311

I'm sorry I meant that I have seen the schrader valves on the FUEL INJECTOr RAILS. not their lines.

Texas_Ace

The system can be done via that port or you can directly tie into the fuel line. I know I had the motorvac treatment done on my 4runner a few years ago and they had no problems. Basically you hook it up and then let it idle for an hour or so, revving it here and there if you feel like it.

Kinda pricy for an individual though, when I looked at them they were over $1k used.

mitfan311

Thats basically what i did but using the line at the point of the fuel filter. It wouldnt rev well but idled for a good 20 mins. Then I let it sit while still hooked up for about 3 hours. Came back and ran it another 15 mins or so. I just started checking around online for different devices. Napa has one they are proud of for about $350. It lets you use your own mix of choice. What I want to do is show pictures of the process. i have video too but I am not good with computers and I dont think you can just upload a video onto a random post here. It really is amazing to see all the clips together.

Texas_Ace

If you want to upload pictures or videos use a place like photobucket.com